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Gouraud Shading
Gouraud shading ( ), named after Henri Gouraud (computer scientist), Henri Gouraud, is an interpolation method used in computer graphics to produce continuous shading of surfaces represented by Polygon mesh, polygon meshes. In practice, Gouraud shading is most often used to achieve continuous lighting on triangle meshes by computing the lighting at the corners of each triangle and Linear interpolation, linearly interpolating the resulting colours for each pixel covered by the triangle. Gouraud first published the technique in 1971. However, enhanced hardware support for superior shading models has yielded Gouraud shading largely obsolete in modern rendering. Description Gouraud shading works as follows: An estimate to the Normal (geometry), surface normal of each Vertex (geometry), vertex in a polygonal 3D model is either specified for each vertex or found by averaging the surface normals of the polygons that meet at each vertex. Using these estimates, lighting computations ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D3D Shading Modes
D3D may refer to: * DIII-D (tokamak) (pronounced 'D3D'), a tokamak located at San Diego, California * Direct3D, Microsoft's graphics rendering scheme * Dolby 3D * Duke Nukem 3D ''Duke Nukem 3D'' is a 1996 first-person shooter, first-person shooter game developed by 3D Realms and published by FormGen for MS-DOS. It is a sequel to the platform games ''Duke Nukem (video game), Duke Nukem'' and ''Duke Nukem II'', published ... or Duke3d, a first person shooter video game from 1996 * China Railways HXD3D, a type of electric locomotive in China {{Letter-NumberCombDisambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shading
Shading refers to the depiction of depth perception in 3D models (within the field of 3D computer graphics) or illustrations (in visual art) by varying the level of darkness. Shading tries to approximate local behavior of light on the object's surface and is not to be confused with techniques of adding shadows, such as shadow mapping or shadow volumes, which fall under global behavior of light. In drawing Shading is used traditionally in drawing for depicting a range of darkness by applying media more densely or with a darker shade for darker areas, and less densely or with a lighter shade for lighter areas. Light patterns, such as objects having light and shaded areas, help when creating the illusion of depth on paper. There are various techniques of shading, including cross hatching, where perpendicular lines of varying closeness are drawn in a grid pattern to shade an area. The closer the lines are together, the darker the area appears. Likewise, the farther apart the lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blinn–Phong Reflection Model
The Blinn–Phong reflection model, also called the modified Phong reflection model, is a modification developed by Jim Blinn to the Phong reflection model in 1977. Blinn–Phong is a shading model used in OpenGL and Direct3D's fixed-function pipeline (before Direct3D 10 and OpenGL 3.1), and is carried out on each vertex as it passes down the graphics pipeline; pixel values between vertices are interpolated by Gouraud shading by default, rather than the more computationally-expensive Phong shading. Description In Phong shading, one must continually recalculate the dot product R \cdot V between a viewer (''V'') and the beam from a light-source (''L'') reflected (''R'') on a surface. If, instead, one calculates a ''halfway vector'' between the viewer and light-source vectors, : H = \frac R \cdot V can be replaced with N \cdot H, where N is the Normalized vector, normalized surface normal. In the above equation, L and V are both normalized vectors, and H is a solution to the eq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Common Shading Algorithms
{{Short description, none This article lists common shading algorithms used in computer graphics. Interpolation techniques These techniques can be combined with any illumination model: * Flat shading * Gouraud shading * Phong shading Illumination models Realistic The illumination models listed here attempt to model the perceived brightness of a surface or a component of the brightness in a way that looks realistic. Some take physical aspects into consideration, like for example the Fresnel equations, microfacets, the rendering equation and subsurface scattering. Diffuse reflection Light that is reflected on a non-metallic and/or a very rough surface gives rise to a diffuse reflection. Models that describe the perceived brightness due to diffuse reflection include: * Lambert * Oren–Nayar (Rough opaque diffuse surfaces) * Minnaert Specular reflection Light that is reflected on a relatively smooth surface gives rise to a specular reflection. This kind of reflection is espe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mach Bands
Mach bands is an optical illusion named after the physicist Ernst Mach. It exaggerates the contrast between edges of the slightly differing shades of gray, as soon as they contact one another, by triggering edge-detection in the human visual system. The Mach band illusion is sometimes called the Chevreul illusion. Explanation The Mach bands effect is due to the spatial high-boost filtering performed by the human visual system on the luminance channel of the image captured by the retina. Mach reported the effect in 1865, conjecturing that filtering is performed in the retina itself, by lateral inhibition among its neurons. This conjecture is supported by observations on other (non-visual) senses, as pointed out by Georg von Békésy. The visual pattern is often found on curved surfaces subject to a particular, naturally-occurring illumination, so the occurrence of filtering can be explained as the result of learnt image statistics. The effect of filtering can be modeled as a co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graphics Processing Unit
A graphics processing unit (GPU) is a specialized electronic circuit designed for digital image processing and to accelerate computer graphics, being present either as a discrete video card or embedded on motherboards, mobile phones, personal computers, workstations, and game consoles. GPUs were later found to be useful for non-graphic calculations involving embarrassingly parallel problems due to their parallel structure. The ability of GPUs to rapidly perform vast numbers of calculations has led to their adoption in diverse fields including artificial intelligence (AI) where they excel at handling data-intensive and computationally demanding tasks. Other non-graphical uses include the training of neural networks and cryptocurrency mining. History 1970s Arcade system boards have used specialized graphics circuits since the 1970s. In early video game hardware, RAM for frame buffers was expensive, so video chips composited data together as the display was being scann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diminishing Returns
In economics, diminishing returns means the decrease in marginal (incremental) output of a production process as the amount of a single factor of production is incrementally increased, holding all other factors of production equal ('' ceteris paribus''). The law of diminishing returns (also known as the law of diminishing marginal productivity) states that in a productive process, if a factor of production continues to increase, while holding all other production factors constant, at some point a further incremental unit of input will return a lower amount of output. The law of diminishing returns does not imply a decrease in overall production capabilities; rather, it defines a point on a production curve at which producing an additional unit of output will result in a lower profit. Under diminishing returns, output remains positive, but productivity and efficiency decrease. The modern understanding of the law adds the dimension of holding other outputs equal, since a giv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tessellation (computer Graphics)
In computer graphics, tessellation is the dividing of datasets of polygons (sometimes called ''vertex sets'') presenting objects in a scene into suitable structures for Rendering (computer graphics), rendering. Especially for Real-time computer graphics, real-time rendering, data is polygon triangulation, tessellated into triangles, for example in OpenGL, OpenGL 4.0 and Direct3D 11. In graphics rendering A key advantage of tessellation for realtime graphics is that it allows detail to be dynamically added and subtracted from a 3D polygon mesh and its silhouette edges based on control parameters (often camera distance). In previously leading realtime techniques such as parallax mapping and bump mapping, surface details could be simulated at the pixel level, but silhouette edge detail was fundamentally limited by the quality of the original dataset. In Direct3D 11 pipeline (a part of DirectX 11), the graphics primitive is the Bézier curve, patch. The ''tessellator'' generates a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specular Highlight
A specular highlight is the bright spot of light that appears on shiny objects when illuminated (for example, see image on right). Specular highlights are important in 3D computer graphics, as they provide a strong visual cue for the shape of an object and its location with respect to light sources in the scene. Microfacets The term ''specular'' means that light is specular reflection, perfectly reflected in a mirror-like way from the light source to the viewer. Specular reflection is visible only where the surface normal is oriented precisely halfway between the direction of incoming light and the direction of the viewer; this is called the half-angle direction because it bisects (divides into halves) the angle between the incoming light and the viewer. Thus, a specularly reflecting surface would show a specular highlight as the perfectly sharp reflected image of a light source. However, many shiny objects show blurred specular highlights. This can be explained by the existe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phong Shading
In 3D computer graphics, Phong shading, Phong interpolation, or normal-vector interpolation shading is an interpolation technique for surface shading invented by computer graphics pioneer Bui Tuong Phong. Phong shading interpolates surface normals across rasterized polygons and computes pixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a Raster graphics, raster image, or the smallest addressable element in a dot matrix display device. In most digital display devices, p ... colors based on the interpolated normals and a reflection model. ''Phong shading'' may also refer to the specific combination of Phong interpolation and the Phong reflection model. History Phong shading and the Phong reflection model were developed at the University of Utah by Bui Tuong Phong, who published them in his 1973 Ph.D. dissertation and a 1975 paper.Bui Tuong Phong, "Illumination for Computer Generated Pictures," Comm. AC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flat Shading
Shading refers to the depiction of depth perception in 3D models (within the field of 3D computer graphics) or illustrations (in visual art) by varying the level of darkness. Shading tries to approximate local behavior of light on the object's surface and is not to be confused with techniques of adding shadows, such as shadow mapping or shadow volumes, which fall under global behavior of light. In drawing Shading is used traditionally in drawing for depicting a range of darkness by applying media more densely or with a darker shade for darker areas, and less densely or with a lighter shade for lighter areas. Light patterns, such as objects having light and shaded areas, help when creating the illusion of depth on paper. There are various techniques of shading, including Hatching, cross hatching, where perpendicular lines of varying closeness are drawn in a grid pattern to shade an area. The closer the lines are together, the darker the area appears. Likewise, the farther apart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
